Barua Rajesh, Malone Jenna, Boutsalis Peter, Gill Gurjeet, Preston Christopher
School of Agriculture, Food and Wine, University of Adelaide, Glen Osmond, Australia.
Pest Manag Sci. 2022 Apr;78(4):1377-1385. doi: 10.1002/ps.6754. Epub 2021 Dec 27.
In initial screening, glyphosate was ineffective in controlling five Poa annua populations. These populations were tested for resistance, and studies undertaken to determine resistance mechanisms and inheritance pattern.
Dose-response studies conducted at 16/12°C and 27/20°C on the five putative resistant populations showed low-level resistance (1.4- to 2.5-fold) to glyphosate. Shikimic acid accumulation in response to glyphosate confirmed differences among the populations, with greater shikimic acid accumulation in the susceptible population. The EPSPS gene copy number was 0.5- to 5.2-fold greater in one resistant population (HT) than in the susceptible (S) population, but not in the others. EPSPS gene expression was five- to tenfold higher in HT compared with the susceptible population. Target site mutations, differences in glyphosate absorption or translocation or altered expression of aldo-keto reductase (AKR) were not identified in any of the resistant populations. Crosses were successful between one resistant population and the susceptible population (P262-16♂ ✕ S♀) and inheritance of glyphosate resistance appears to be controlled by a single, nuclear dominant gene in this population.
Our study identified EPSPS gene amplification in a South Australian glyphosate-resistant P. annua population (HT). This mechanism of resistance was not identified in the other four glyphosate-resistant populations, and other common mechanisms were excluded. Although the resistance mechanism in some P. annua populations remains unknown, inheritance studies with one population suggest the involvement of a single dominant gene. © 2021 Society of Chemical Industry.
在初步筛选中，草甘膦对五个一年生早熟禾种群的防除效果不佳。对这些种群进行了抗性测试，并开展研究以确定抗性机制和遗传模式。
在16/12°C和27/20°C条件下对五个假定的抗性种群进行剂量反应研究，结果表明它们对草甘膦具有低水平抗性（1.4至2.5倍）。草甘膦处理后莽草酸的积累证实了种群间的差异，敏感种群中莽草酸积累更多。一个抗性种群（HT）的5-烯醇丙酮酰莽草酸-3-磷酸合酶（EPSPS）基因拷贝数比敏感种群（S）高0.5至5.2倍，但其他种群未出现这种情况。与敏感种群相比，HT种群中EPSPS基因表达高5至10倍。在任何抗性种群中均未发现靶标位点突变、草甘膦吸收或转运差异或醛酮还原酶（AKR）表达改变。一个抗性种群与敏感种群（P262-16♂×S♀）杂交成功，在该种群中，草甘膦抗性的遗传似乎由一个单基因核显性基因控制。
我们的研究在南澳大利亚一个抗草甘膦的一年生早熟禾种群（HT）中发现了EPSPS基因扩增。在其他四个抗草甘膦种群中未发现这种抗性机制，且排除了其他常见机制。尽管一些一年生早熟禾种群的抗性机制尚不清楚，但对其中一个种群的遗传研究表明涉及一个单显性基因。©2021化学工业协会。
